1. Field of the Invention
This invention relates to chain drivers for lifting and lowering loads of a manual chain hoist, and in particular to a portable, motorized, chain driver easily carried by a chain hoist operator.
2. Description of Related Art
There are many chain hoist mechanisms in the prior art which are used in industry particularly on mechanical handling of materials in shops and warehouse employing hoists, and which may be geared and electrically driven, hydraulically driven, or manually driven via an endless chain. Typically, hoists extend from overhead monorail systems and can be either manual or power driven. They also are portable, and it is desirable that they not be too heavy so that they can be easily moved from one location to another.
For example, U.S. Pat. No. 2,991,976 issued Jul. 11, 1961 to Charles Carroll and assigned to Duff-Norton Company of Pittsburg, Pa. discloses a power driven hoist driven by an electric motor which powers a chain and is normally coupled to an overhead monorail trolley.
Other prior art patents include U.S. Pat. No. 836,789 issued Nov. 27, 1906 to Walter N. Vance and assigned to Yale and Towne Manufacturing company of Stamford, Conn. discloses a portable electric hoist comprising a chain-block, an electric motor and an electric controller located on the opposite side of the chain block and they all rest in the same horizontal plane. However, this hoist is not held by an operator when hoisting a load.
U.S. Pat. No. 4,646,805 issued Mar. 3, 1987 to Hans-Otto Dohmeier of Johannesburg, South Africa discloses a chain winch having a sprocket wheel of polygonal cross-section with flat faces dimensioned in dependence on the dimensions of a link chain to be used therewith and having pin formations for engaging between or in the chain links. However, it does not disclose a hand held portable chain driver.
None of the above patents disclose the structural features of the present invention, which is intended to be portable and drive a manual chain hoist.
Accordingly, it is therefore an object of this invention to provide a portable hand held tool that attaches to a manual chain hoist to drive hand chains, lifting and lowering the hoist""s load.
It is another object of this invention to provide a portable, motorized, chain driver that attaches to and hangs from each side of circulator hoist hand chains at any desired location along the chains.
It is another object of this invention to provide a portable motorized chain driver that operates manual chain driver garage doors.
It is a further object of this invention to provide means for switching the direction of the chain or chains being driven by the chain driver and to provide variable speed control.
It is another object of this invention to provide a rotor assembly comprising a pocket wheel, a sprocket wheel, and a clutch disc for moving the chain through the chain driver.
These and other objects are accomplished by a portable chain driver comprising a chain and rotor housing for receiving links of a chain, and a power source attached to the chain and rotor housing for driving the chain through the housing. The chain and rotor housing comprises means for securing a chain pail under the housing. The chain and rotor housing comprises a front housing and a rear housing, the front housing and the rear housing comprise means for securing the front housing and the rear housing together. The securing means comprises a first hinge pin on a first side of the housing and a second hinge pin on a second side of the housing wherein removal of one hinge pin allows the front housing to swing open for installing or removing the chain. The chain and rotor housing comprises a front housing and a rear housing secured together, chain guides on each side of the front housing and the rear housing, a rotor assembly positioned within the housing and extending through the rear housing, and means attached to the rotor assembly and extending through the front housing for controlling the operation of the rotor assembly. The chain and rotor housing comprises a rotor assembly including a chain pocket wheel and a chain sprocket wheel attached within the chain pocket wheel. The power source comprises means for driving the chain in the housing with an electrical power source. The power source may also comprise means for driving the chain in the housing with a gas driven power source. The power source comprises a handle. The handle comprises means for selecting the direction and speed of the chain passing through the housing. Also, the handle location and position optimizes means of reacting to the rotor torque and hoist loads. The chain and rotor housing comprises a rotor assembly enclosed within a front housing and a rear housing of the chain and rotor housing, and means for interfacing the rotor assembly to the power source. The rotor assembly comprises a rotor, a rotor centering hub positioned through the front housing and into a center portion of the rotor, a bushing positioned around the rotor centering hub, a clutch disc having a first end positioned adjacent to the rotor, a drive shaft inserted into the clutch disc and attached within the rotor centering hub, and a spring pack positioned adjacent to a second end of the clutch disc, the drive shaft passing through the spring pack. The rotor centering hub further comprises a clutch cam lever located within an end of the rotor centering hub for engaging and disengaging the clutch disc. The rotor centering hub comprises a lock screw for attaching the rotor centering hub to the drive shaft. The drive shaft comprises a hex portion for insertion into a hex receiving section of the clutch disc.
The objects are further accomplished by a method of providing a portable chain driver comprising the steps of positioning links of a chain in a chain and rotor housing, and attaching a power source to the chain and rotor housing for driving the chain through the housing. The step of positioning links of a chain in the chain and rotor housing comprises the steps of providing the chain and rotor housing with a front housing section and a rear housing section, and opening the front housing section to install or remove the links of the chain. The method comprises the steps of providing the chain and rotor housing with a chain sprocket wheel attached within a chain pocket wheel, and providing a rotor assembly having a shaft passing into the chain and rotor housing. The step of providing the chain and rotor housing with a chain sprocket wheel attached within a chain pocket wheel comprises the step of providing the sprocket wheel in sections which are secured to the pocket wheel. The step of attaching a power source comprises the step of attaching an electrically driven power source. The step of attaching a power source also comprises the step of attaching a gas driven power source. The method comprises the step of attaching a pail under the chain and rotor housing for collecting the chain passing through the chain driver.
Additional objects, features and advantages of the invention will become apparent to those skilled in the art upon consideration of the following detailed description of the preferred embodiments exemplifying the best made of carrying out the invention as presently perceived.